More particularly, the invention relates to a device for measuring the concentration of a predetermined gas, comprising a cavity holding the predetermined gas in a concentration to be measured, a light source capable of emitting light rays within the cavity, particularly infrared rays, and an infrared detector configured to receive a portion of the infrared rays within a predetermined spectral range corresponding to high absorption of the predetermined gas.
It is known from prior art document U.S. Pat. No. 8,003,944 to place a second infrared detector in order to create a reference channel which allows eliminating the slow drifts related to aging of the lamp for example. The detectors in question are expensive and bulky. In addition, their power consumption is a disadvantage.
There is therefore a need to optimize this kind of device to reduce the cost and size, but without diminishing their performance and accuracy.